EDIT: RESOLVED - quitting browser and restarting showed the new Filter feature
It used to be in the menu section as "Search Cards' or something like that. A bit confusing to find but it worked at least. Now you need to use a keyboard shortcut "f" to filter cards but there is zero on the desktop version to point you to this functionality. Not user friendly at all. Come on Trello, why did you take this functionality away?
